U.S. patent number 7,151,439 [Application Number 10/957,794] was granted by the patent office on 2006-12-19 for device for improving the visibility conditions in a motor vehicle.
This patent grant is currently assigned to DaimlerChrysler AG. Invention is credited to Michael Holz, Joerg Moisel.
United States Patent |
7,151,439 |
Moisel , et al. |
December 19, 2006 |
Device for improving the visibility conditions in a motor
vehicle
Abstract
A device for improving the visibility conditions in a motor
vehicle has a radiation source for infrared radiation for
irradiating the surroundings of the vehicle, an infrared-sensitive
camera for taking images of at least part of the irradiated
surroundings, a display unit for displaying collected image data,
and a control unit for controlling the device. The control unit is
configured in such a way that the display is switched off after a
predefined time period t has expired. This device ensures very safe
operation for the user.
Inventors: |
Moisel; Joerg (Neu-Ulm,
DE), Holz; Michael (Senden, DE) |
Assignee: |
DaimlerChrysler AG (Stuttgart,
DE)
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Family
ID: |
33395118 |
Appl.
No.: |
10/957,794 |
Filed: |
October 4, 2004 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050073581 A1 |
Apr 7, 2005 |
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Foreign Application Priority Data
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Oct 2, 2003 [DE] |
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103 46 482 |
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Current U.S.
Class: |
340/425.5;
348/164; 348/148; 348/E5.09 |
Current CPC
Class: |
G02B
23/12 (20130101); G01S 17/931 (20200101); G02B
27/01 (20130101); H04N 5/33 (20130101); G01S
17/89 (20130101); B60R 1/00 (20130101); B60K
2370/21 (20190501); B60R 2300/302 (20130101); B60R
2300/404 (20130101); B60R 2300/106 (20130101); B60R
2300/8053 (20130101); B60R 2300/103 (20130101) |
Current International
Class: |
B60Q
1/00 (20060101); H04N 7/18 (20060101) |
Field of
Search: |
;340/425.5,426.6,441,433
;348/148,164 ;250/330,334 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Crosland; Donnie L.
Attorney, Agent or Firm: Akerman Senterfitt Chen; Yonghong
Pendorf; Stephan
Claims
The invention claimed is:
1. A device for improving the visibility conditions in a motor
vehicle, comprising: a radiation source for infrared radiation for
irradiating the surroundings of the vehicle, an infrared-sensitive
camera for collecting radiation reflected from at least part of the
irradiated surroundings and converting the radiation into image
data, a display unit for displaying the image data, and a control
unit for controlling the device, wherein the control unit has a
switch for switching off the display after a predefined time period
t has expired.
2. The device according to claim 1, wherein the switch, in addition
to the display, switches off the camera and/or the radiation source
after a predefined time period t.sub.k.
3. The device according to claim 1, further comprising an
additional switch for switching on the display after switching off
occurs.
4. The device according to claim 3, wherein the additional switch
is implemented in a region of the steering wheel, in particular by
a headlamp flasher or a steering wheel rocker.
5. The device for according to claim 1, wherein the display is
switched off suddenly.
6. The device according to claim 1, wherein the switching off of
the display is gradual.
7. The device according to claim 1, wherein the control unit is
configured in such a way that before the switching off takes place
the control unit causes the switching off to be signaled.
8. The device according to claim 7, wherein a residual running time
is displayed for the purpose of signaling.
9. The device according to claim 1, wherein the time period t lies
in the minute range, in particular in the range of half a
minute.
10. The device according to claim 1, wherein the time period t is
adjustable.
11. The device according to claim 1, wherein the control unit is
embodied in such a way that switching off occurs when a vehicle
velocity v above a predefined maximum velocity v.sub.max is
exceeded.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a device for improving the visibility in a
motor vehicle.
2. Related Art of the Invention
DE 40 32 927 C2 discloses a device for improving the visibility in
a motor vehicle having a radiation source for infrared radiation
for irradiating the surroundings of the vehicle, and having an
infrared-sensitive camera which takes images of the irradiated
field of vision of the driver and makes available the collected
image data to the driver by means of a display device which is
embodied as a head-up display and in which the image data is
visually superimposed as a virtual image on the external landscape.
By means of this device, the driver can see considerably better at
night or in bad weather conditions, in particular when he is
dazzled by oncoming vehicles. As a result of the use of infrared
radiation, the driver is, in contrast, not dazzled by the oncoming
traffic. Such devices of this type are called night vision
systems.
By virtue of the improved visibility, the vehicle driver may be
tempted to look exclusively at the display and not to observe the
surroundings directly any more, which can lead to
misinterpretations. In particular there is the risk of the field of
vision being overestimated and of driving too quickly owing to the
supposedly better visibility.
SUMMARY OF THE INVENTION
The invention is based on the object of specifying a device for
improving the visibility conditions in a motor vehicle which
reduces these disadvantages and as a result improves traffic
safety.
This object is achieved by means of a device for improving the
visibility conditions in a motor vehicle having the features of
claim 1.
Advantageous developments of the device are the subject matter of
the subclaims.
The device according to the invention for improving the visibility
conditions in a motor vehicle ensures that the display is switched
off under the control of the control unit after the expiry of a
predefined time period t, and the representation of the collected
image data is thus interrupted. As a result of this targeted
interruption of the representation of images it is ensured that the
user of the vehicle cannot concentrate continuously and thus
exclusively on the display and have only the display in his field
of vision and steer the vehicle only on the basis of the image
data. This therefore ensures that the driver looks away from the
display at the latest when the time period t expires and considers
the real surroundings of the vehicle and again uses this
information to make the decisions in order to drive the vehicle. As
a result of this form of operation of the device it is therefore
ensured that the respectively useful and positive advantages of the
collected information directly from the surroundings and from the
display, respectively, complement one another without significant
associated disadvantages.
Furthermore, it is possible, since the mode of operation of the
device forces the driver to stop looking at the representation of
the surroundings on the display, to reduce the risk of tending to
overestimate the visibility conditions and thus the risk of driving
too fast since the vehicle driver cannot rely only on the improved
visibility which is provided by the device according to the
invention. Overall, these aspects lead to an improvement in the
safety of the vehicle driver or the driver and thus also of the
traffic as a whole and the persons involved in it.
The time period t is preferably selected in the range of less than
one minute, in particular in a range between 2 and 30 seconds. It
has also proven effective to select a time period t which is longer
than a minute or in the region of several minutes. These time
periods ensure that the vehicle driver is provided with sufficient
reliable information by the device according to the invention which
permits improved visibility at night or in bad weather. This
improved visibility reduces the risk of accidents, the selective
termination of the representation of image data on the display
ensuring that the negative effects of this improved representation
of the surroundings on the basis of the infrared radiation which is
reflected by the surroundings and which is sensed via the
infrared-sensitive camera and represented on the display do not
occur, or occur only to a limited degree.
It has proven particularly effective to store the predefined time
period permanently in the device and/or for it to be re-stored with
modified time periods as part of maintenance operations by the
specialist personnel department. Furthermore, it is conceivable for
the predefined time to be able to be changed by the user and for
the modified time period then to be able to be used as the basis of
the switching off of the representation on the display. This device
proves very flexible and very user-friendly. Nevertheless it has
proven effective not to give the vehicle driver a complete control
over the predefined time period t so that he does not select a
maximum time period t which is too long as a result of which the
positive inventive effect is dramatically restricted. Furthermore,
it has proven particularly effective to change the time period t in
accordance with the situation. For example, it has proven effective
in the case of very bendy sections of road or stretches of road
with a layout which is unfavourable for visibility to select a
short time period t, which is done by the control unit. This device
ensures that a very effective time period t is selected, which
ensures a considerable increase in safety depending on the
situation.
According to one preferred embodiment of the device, the control
unit is embodied in such a way that the camera can be switched off
in addition to the display. Here, the camera is switched off after
a predefined time period t.sub.K. The time period t.sub.K can be of
equal length to the time period t or longer than it. This ensures
that the device operates efficiently and reliably without the
operational capability of the device being restricted. Making a
selection of the time period t.sub.K which is only slightly longer
than the time period t ensures that the camera is not switched off
before the display and that in addition the camera as a large
energy consumer, which can only be re-activated very slowly, is not
switched off too early with the display or directly after it.
Alternatively or additionally to the camera, the radiation source
is also switched on and off under the control of the control unit.
In this case, the control unit ensures that the time period t and
the time period t.sub.K begin to run starting from the same
switch-on time.
According to another preferred embodiment of the invention, in
addition to the on and off switch for the device, an additional
switch is provided for switching on the display and/or the camera.
This additional switch permits the active, conscious switching on
of the representation of images on the display after the display or
the camera has been switched off after the time periods t and
t.sub.K have expired. This ensures that the vehicle driver can
completely activate the device as required by activating the
additional switch, and can thus obtain the advantage of improved
visibility. It has proven particularly effective here to implement
the additional switch in the region of the steering wheel in
particular in the form of a headlamp flasher or a rocker on the
steering wheel. The arrangement of the additional switch in the
region of the steering wheel makes it possible to activate the
switch without the driver having to completely take one or both
hands off the steering wheel. This leads to very safe handling of
the device and thus to an increase in road safety. The use of the
headlamp flasher as an additional switch for the device has proven
particularly effective, ensuring that, by activating the headlamp
flasher, not only the headlamp flashing function but also the
display and the camera are re-activated. This leads to a situation
in which the surroundings of the vehicle which are irradiated by
the infrared radiation source are at least partially sensed by the
camera and the collected image data can be displayed on the
display. When switching on occurs, the time which has passed since
the switching on is determined in the control unit in order to
compare this time with the time period t or t.sub.K in order then
to switch off the display, the radiation source or the camera when
these time periods are reached.
It has proven particularly effective to restrict the representation
of the collected image data by the display essentially to the time
period when a switch is activated, and accordingly to select a very
short time period t, in an extreme case equal to 0 seconds. This
ensures that a vehicle driver makes use of the device according to
the invention when required, for example when dazzled by oncoming
traffic at night, and otherwise concentrates on sensing the
surroundings directly, which significantly reduces the risk of
overestimating a situation.
It has proven particularly advantageous to make the switching off
of the display, that has to say the termination of the
representation of images, sudden, that is to say abrupt. This has
the advantage that a very simple control of the device, which is
not very susceptible to faults, is sufficient to obtain this
positive effect according to the invention for increasing road
safety.
Furthermore, according to another embodiment of the invention it
has proven effective to make the switching-off process gradual so
that the reproduction of images does not change abruptly but rather
gradually, over a certain time period, from the complete
representation of image data to the switched-off state without
representation of image data. In this context, this gradual
switching off can be brought about, for example, by restricting the
brightness values or contrast values of the representation of
images or of the display in such a way that an increasingly low
brightness range or contrast range is continuously made available.
This reduction of the brightness range or contrast range is
continued until these ranges have dropped to zero and thus the
display is switched off. Alternatively, it has also proven
effective for this purpose to disassociate the image data by means
of artificial noise and to make the disassociation become stronger
and stronger, which is brought about by increasing the proportion
of noise until the image data can virtually no longer be perceived.
This state corresponds to the switched-off display since this
display is no longer suitable for displaying the image data to be
displayed which relates to the sensed surroundings which are
irradiated by infrared light. This switching-off process is
preferably implemented as a linearly extending gradual transition,
which is made possible by means of a control which is not too
complicated. Alternatively, nonlinear processes are also
conceivable. This embodiment of the device according to the
invention with a gradual switching-off process ensures that the
user receives information about the imminent final termination of
the representation of images before the final switching off of the
representation of images on the display, and is thus not
unpleasantly surprised. This has a positive effect on the reduction
of the risk of accidents.
It has also proven particularly effective to signal the switching
off to the vehicle driver before the switching off is carried out.
This signalling is carried out, for example, by means of a visual
representation on the display, alternatively or additionally by
means of haptic signalling, for example by vibrating the steering
wheel or by means of an audible signal, for example by the sounding
of a short tone. This advance information before the switching off
is carried out ensures that the driver is prewarned to a particular
degree before the switching off is carried out. This leads to an
improvement in road safety. Audible warning signals have proven
particularly effective since they can also be perceived without
visual contact with the display, for example during the direct
consideration of the surroundings of the vehicle, and can thus be
perceived by the vehicle driver at regular intervals without
interruptions or with only short interruptions in such a way that
he is not surprised by the switching off of the display or the
representation of images on the display.
It has proven effective to represent the residual running time on
the display as a particularly preferred way of signalling the
imminent switching off so that the vehicle driver is always
informed about the remaining time until the camera or the display
is switched off. This representation is preferably made in seconds
or else in the form of a bar diagram. In particular a bar diagram
representation proves a very intuitive form of representation which
is easy to comprehend and which is sufficiently reliable in
providing the driver with a warning while simultaneously not
distracting him very much. This form of representation of the
signalling in the form of the residual running time, in particular
in the form of the bar representation, provides a very reliable and
informative warning about the switching off of the representation
on the display, which leads to very reliable operation of the
device and thus to a considerable increase in road safety.
According to one particularly preferred embodiment of the device,
the control unit is embodied in such a way that the current vehicle
velocity can be fed to it and it controls the switching off in such
a way that the display or the camera is switched off when the
vehicle velocity V exceeds a predefined maximum velocity. In this
case, it is ensured that the vehicle driver cannot rely on the
subjective impression of particularly good, overestimated
visibility and correspondingly selects his vehicle velocity V
inappropriately high in accordance with his misinterpreted field of
vision. As a result of the velocity-dependent switching off when a
maximum velocity V.sub.max is exceeded, it is ensured that the
vehicle driver is forced to rely on the direct sensing of the
surroundings of the vehicle, i.e. for example to rely on the usual
sensing of the surroundings of the vehicle at night or when
visibility is poor and not to use the improved visibility by means
of the device which can be made available to him via the display.
As a result of this switching off he is forced to consider his
velocity at regular intervals since the improved visibility is no
longer available to him and correspondingly he must select his
driving velocity in accordance with the actual visibility in the
visible range, that is to say without support by infrared
radiation, and correspondingly must make a reduced selection. This
leads to a situation in which the driver then reduces his driving
velocity regularly on the basis of the poorer visibility, which
leads to a situation in which the device can be fully actuated
again when the velocity drops below a corresponding velocity limit
and the improved visibility of the surroundings of the vehicle
which is acquired by means of the device can be made available to
the driver.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be explained in more detail below with reference
to an exemplary implementation of the device according to the
invention for improving the visibility conditions in a motor
vehicle. The invention is not restricted to this embodiment.
FIG. 1 shows a schematic design of the device according to the
invention for improving the visibility conditions in a motor
vehicle.
DETAILED DESCRIPTION OF THE INVENTION
This device exhibits a radiation source 2 for infrared radiation
which irradiates infrared radiation with a wavelength of
approximately 800 nm. The radiation source 2 is implemented as an
infrared laser. This radiation source 2 is arranged in the front
region of the vehicle in the region of the headlights and
irradiates the region in front of the vehicle. In addition, this
device has an infrared-sensitive camera 3 which is arranged in the
vehicle and is orientated in such a way that it senses at least
part of the surroundings which are irradiated by the infrared
radiation source 2, and feeds the collected image data to the
display 4 via the control unit 1. By means of the display 4, the
image data which is fed to it and collected by the camera 3 is
displayed and thus made available to a vehicle driver. The control
unit 1 controls the infrared radiation source 2, the camera 3 and
the display 4 in this context.
The infrared radiation source 2 radiates infrared radiation here,
which is reflected at least partially from the surroundings and
collected by the infrared-sensitive camera 3 as reflected radiation
and converted into image data. This image data is represented by
the display 4 either directly or after a certain degree of image
signal processing by means of the image evaluation unit 6. As a
result, the image which is represented on the display 4 is an
infrared representation of the surroundings of the vehicle. Since
the infrared reflective properties and irradiation properties of
the surroundings differ from the properties in the visible light
range, the image represented will also differ from the direct view
of the surroundings by the vehicle driver. By using the device it
is possible to use these differences advantageously, which leads to
improved visibility in particular at night, but also in bad weather
conditions such as in the rain or in fog.
The control unit 1 controls the display 4 here in such a way that
after a predefined time period t has expired the representation of
images on the display 4 is terminated and the display 4 is thus
switched off. It is not necessary to completely switch off the
display 4; for the operational capability of the device according
to the invention it is sufficient to merely terminate the
representation of images. The switching off of the display 4
requires the vehicle driver to look away from the display 4 and to
direct his gaze directly on to the surroundings of the vehicle
again. This ensures that he cannot be dazzled by the improved
visibility which is provided by the device according to the
invention and, owing to the improved visibility, misinterprets his
own capabilities, the vehicle or the external circumstances and,
for example, drives too quickly or with an inappropriate velocity.
Instead, the switching off of the display 4 causes him to turn his
attention directly to the surroundings of the vehicle and to adapt
his driving behavior in an orderly manner to the visibility
conditions which are then available to him and to use again the
improved visibility after the device or the representation of
images of the display 4 has been switched on again, without
automatically being subject to a misinterpretation of the
situation. This effect has proven very advantageous and very
acceptable. In addition to the switching off of the display 4 after
a time period t, the control unit 1 also has the control function
of switching off the camera 3 after a time period t.sub.K which is
one minute longer than time period t, which is in the region of one
minute or half a minute. This additional control function ensures
very effective operation of the device, in which case, on the one
hand, the operational capability of the device is maintained
without restriction but, on the other hand, the consumption of
energy of the device is markedly reduced. The consumption of energy
of such a device is of particular significance in a vehicle since
such a vehicle has a large number of electronic components of which
a large number operate simultaneously and correspondingly consume a
considerable amount of energy which the vehicle, with its
autonomous energy supply, can make available only to a limited
degree.
Furthermore, the control unit 1 is connected to the headlamp
flasher 5 which is arranged as an additional switch in the region
of the steering wheel. The actuation of the headlamp flasher switch
causes the display 4 or the camera 3 to be actuated again and
switched on again under the control of the control unit 1. As a
result, the timing process is restarted and the display 4 or the
camera 3 is kept operational until the time periods t and t.sub.K
have passed and the display 4 or the camera 3 is switched off as a
function thereof. As a result of this simple embodiment of an
additional switch for switching on the display 4 or the camera 3, a
very robust and safe and easy-to-handle device is provided which,
on the one hand, makes available improved visibility for the
vehicle driver, and on the other hand prevents undesired driving
only in accordance with the display, and on the other hand permits
actuation without significant difficulties. By using the headlamp
flasher switch 5 it is possible for the driver to activate the
display 4 or the camera 3 by actuating the headlamp flasher in
parallel, without the driver having to release the steering wheel
from his secure grip. This leads to very safe handling of the
device and thus to an increase in road safety.
The control unit 1 is connected to an image evaluation unit 6 which
carries out the termination of the representation of images, and
thus the switching off of the display 4, in a gradual fashion. In
this context, the collected image data is artificially degraded
during the gradual switching off by adding noise components until
only noise is represented on the display 4, and the display 4 can
thus be switched off, as it were. As the noise increases, the image
information which can be sensed, and thus the represented image
data, becomes less useful for the vehicle driver, who is
accordingly increasingly inclined to view and sense the
surroundings of the vehicle directly. This gradual switching off
ensures that the vehicle driver is forewarned of the imminent final
switching off and is therefore not surprised by the final switching
off. This has proven very positive for the vehicle driver.
Furthermore, a sensing unit 7 is provided which senses the vehicle
velocity V and feeds it to the control unit 1. This control unit 1
compares the current vehicle velocity V, which has been sensed by
the sensing unit 7, with a predefined maximum velocity V.sub.max.
If the current vehicle velocity V exceeds the maximum velocity
V.sub.max, the control unit 1 will switch off the display 4 in a
corresponding way to the sequence of the time period t. In
addition, the camera 3 is also switched off. When the velocity
drops below the maximum velocity, the switched-off components are
then activated again so that the image data which is collected by
the camera 3 can be made available to the user again on the display
4.
The described device thus exhibits switching off of individual
components 3, 4 as a function of the velocity V at which the
vehicle is travelling or as a function of the operating time of the
display 4 or of the camera 3. This embodiment of the device makes
it possible to limit incorrect preconceptions of the vehicle driver
with respect to the driving situation and thus to increase the road
safety for the vehicle driver, the vehicle and the traffic as a
whole.
* * * * *